Automotive lifting device



Nov. 5, 1935; 'w i STEPHENS 2,019,938

AUTOMOTIVE LIFTING DEVICE Filed Aug. 26, 1935 s sneaks-sh et 1 Nov. 5, 1935."

w. T. STEPHENS I AUTOMOTIVE LIFTING DEVICE Filed Aug.26, i933 3 Sheets-Sheet 2 INVENTOR Nov; 5, 1935.

w. T. STEPHENS 2,019,938 AUTOMOTIVE LI FTING DEVICE Filed Aug. 26, 1955' s Sheets-Sheet a INVENTOR aw may Patented Nov. 5, 1935 UNITED STATES AUTOMOTIVE LIFTING DEVICE William T. Stephens, Youngstown, Ohio, assignor to The Commercial Shearing and Stamping gilililnpany, Youngstown, Ohio, a corporation of Application August 2c, 1933, Serial No. 686,939 8 Claims. ion. 212-8) My invention relates to a lifting device such as a crane or shovel and, in particular, to devices of this type which are of such size and capacity as to be adapted for mounting on automotive vehicles having linked flexible, continuous traction and supporting belts.

It has been proposed previously to mount lifting mechanism on tractors having continuous traction and supporting belts, but all such structures with which I am familiar are characterized bynumerous objectionable features which have greatly restricted their use. In devices of this kind as heretofore constructed, a double drum winch for operating the crane hoist has been mouted on the rear of the tractor. This apparatus, is expensive and is also objectionable because of the considerable weight thereof.

The hoist booms have heretofore been mountedon the tractor chassis which, in turn, is spring mounted on the track frames traversed by the traction'belts. Because of' the resilience of the springs between the chassis and the belt frames, the booms had little or no stability and the lifting capacity was correspondingly limited. Counterbalances were resorted to in an attempt to overcome these objections, but, of course, involved a further increase inthe dead weight. g

In accordance with my invention, I provide a mounting for a lifting device such as a crane or shovel embodying a ported directly on the track frames carrying the traction belts. Since these frames bear directly on the traction belts which rest on the ground or roadway, the mounting is not resilient, but is characterized by a high degree of rigidity and stability. At the same time, the ordinary spring suspension of the tractor chassis is not interfered Instead of a drum type winch, I employ a hydraulically operated reciprocating wind-up mounted adjacent the outer end of the boom. The boom is elevated by hydraulic jacks pivoted thereto andhaving bearing on the traction belt frames. A pump and suitable control valves are provided for supplying fluid under pressure for operating. the boom lifting and wind-up jacks. The pump-is mounted so as to be conveniently driven from the tractor engine.

For a more complete understanding of the invention, reference is made to the accompanying drawings illustrating the present preferred embodiments. In the drawings- Figure 1 is a side elevation of a tractor-mounted crane constructed in accordance with my invention;

Figure 2 is a plan view thereof;

tilting boom, which is sup-' Figure 3 is a partial sectional view along the plane of line III-III of Figure 2;

Figure 4 is a partial end elevation of the inner end of one side of the boom of the crane;

Figure 5 is a view similar to Figure 1, 'show- 5.

ing the invention embodied in a shovel or loader; and a Figure 6 is a partial plan view of the loader of Figure 5.

Referring now in for the moment, to Figures 1 through 4 in particular, a tractor l0 comprises a chassis hav ing an engine mounted thereon within a hood l2. The chassis is spring supported on traction belt or track frames |3 provided with traction and guiding sprockets it around which are trained continuous linked traction belts l5.

Front and rear bearings I6 and I! are secured to the belt frames on opposite sides of the tractor. The front and rear bearings on the same side are connected by channels a A boom 9 fabricated of structural shapes is pivoted on pins 20 extending through the channels H3. The boom l9 comprises outer channels 2| and inner channels 22, bent as illustrated and connected by spacer plates 23 and bracing channels 24. Reinforcing gussets 25 are welded to the ,channels adjacent their bent portions.

A multiple sheave block 26 is carried atthe outer end of the boom IS. A hydraulic jack 21 is mounted adjacent the block and its piston is provided with a corresponding block 28. Guide channels 29 extend between the outer channels 2| and the bracing chanels 24 to provide trackways for the reciprocating block 28. A cable 30 having a weighted hook 3| at its free end is trained successively over the sheaves of the blocks 26 and 28 and has one end fixed in any convenient manner to the boom. The cable is trained over the sheaves in the known manner so that when the jack 2'! is extended, the cable 30 will be wound up at a rate depending on the rate of movement of the block 28 and the multiplying factor of the sheave system which, of course, is determined by the number of sheaves employed.

The jack 21 is double acting, opposite ends thereof being connected by conduits 32 to a. valve 33 which, together with a reservoir 34 and a pump 35 arranged to be driven by the tractor engine, constitute the complete hydraulic system necessary for the operation of the wind-up jack 21. When the jack 21 is retracted, the weight of the hook 3| causes the latter to drop and take up the slack in the cable 30.

The forward bearings l6 have upstanding cars detail to the drawings, and 10,

I6 providing pivotal supports for boom lifting jacks 30. The pistons of the jacks I. are pivoted to pins 81 which extend through hanger plates 30 on opposite sides of the jacks, and secured to the channels 2| and 22. The Jacks ll aresingle acting and each has a conduit 1: extending to a valve Ill connected in thehydraulic system previously described.

It will be apparent that operation of the pump and manipulation of the valve will cause the Jacks 38 to be extended so that the boom I! is lifted successively to elevated positions such as those illustrated in dotted and chain lines respectively in Figure 1, the extent of elevation of the boom being directly under the control of the operator of the valve 41. The hoist jack 21, likewise, controlled by the valve 33, may be operated to any desired extent, to exert the required lift on a load suspended on the hook 3!. The construction illustrated is designed to wind up approximately eighteen feet of the cable 30 which is sufficient for all ordinary service.

The aforementioned advantage as to rigidity and stability of the boom mounting will now be apparent from the specific description given. The boom is pivoted well toward the rear of the tractor on the channels is which are secured to the bearings l6 and I1. The latter are carried directly on the belt frames and, in effect, rest directly on the ground or roadway. The location of the boom hinge Ill permits the crane to lift a heavy load without danger of tipping even though no counter-balancing is employed. With the boom in the chain line position of Figure 1, for example, a device of the character of that illustrated had a capacity of 5000 lbs. An earlier type of tractor crane had a capacity of only 700 lbs, in a similar position, without counter-balancing. Since the boom is generally of yoke shape, it can be lowered to the full horizontal position without interfering with the tractor chassis. A wide operating range is thus provided. The hydraulic jack for the cable hoist is cheaper and lighterthan the drum wind-up, and provides a more flexible control of the load being hoisted.

In a modified form of the invention illustrated in Figures 5 and 6, the principles described above are utilized in the construction of a loader or shovel. The construction of Figures 5 and 6 is quite similar to that of Figures 1 through 4, including a tractor 45 on the traction belt frames of which are mounted front and rear bearings 46 and 4 1, connected by longitudinally extending channels 48. Pins 49 extending through the channels 48 at the rear end thereof provide a pivotal mounting for a boom 50 composed of outer channels 5| and inner channels 52. As shown in' Figure 5. the outer ends of the boom members are bent downwardly to provide bearings for pivotally supporting a shovel 53 thereon. The shovel has counter-weights 54 eflective when the shovel is emptied to retract it to the digging position shown in solid lines in Figure 5.

A retractible detent 55 mounted on a cross beam 56 constituting a brace adjacent the outer ends of the boom members, cooperates with a hook 51 on the shovel. When the shovel is loaded and lifted, the weight of the contents is suillcient to overbalance the counter-weights 54 when the detent 55 is retracted'as by pulling on a dumping cable 5!.

The boom 50 is provided with lifting jacks 5! which are practically identical with corresponding elements of the crane structure already described in detail. These jacks are controlled by a valve til, the hydraulic system including also a reservoir II, a pump, 02 and suitable connecting conduits.

The operation of the shovel of Figures 5 and 6 will be obvious from the description of the struc- 5 ture thereof. When the shovel is lifted and dumped, the counter-weights l4 restore it to digging position with the detent I en888 8 the hook I1.

The automotive shovel just described is characm terized by the same advantages and desirable features as the tractor crane, including the stability of the mounting, the flexibility of control, and its large capacity compared to equipment of corresponding size as heretofore constructed. 15

Although I have illustrated and described herein but two preferred embodiments of my invention, it will be apparent that numerous changes in the details of the apparatus described may be made without departing from the spirit of the in- 20 vent-ion or the scope of the appended claims.

I claim:

1. Lifting apparatus for mounting on an automotive vehicle having traction belts traversing track frames, comprising bearings attached to 25 said frames in spaced relation, longitudinal members supported on said bearings, a boom hinged adjacent the rear end of said longitudinal members, and a hydraulic jack pivoted to one of said bearings and having pivotal connection with 30 said boom.

2. The combination with an automotive vehicle having traction belts traversing track frames, of supports resting on said frames, means on said supports providing a hinge bearing, a boom ex- 35 tending forwardly of the vehicle mounted in said hinge bearing, and a hydraulic Jack pivoted to one of said supports and connected to the boom to cause tilting movement of the latter on extension of the jack.

3. A boom mounting for use on automotive vehicles having traction belts traversing track frames, comprising bearings extending upwardly from said guiding frames, a boom hingedly mounted on said bearings, and a hydraulic Jack 45 pivoted to one of said bearings and connected to the boom to cause tilting movement of the latter on extension of the Jack.

4. The combination with an automotive vehicle having a crawler track frame on each side 5( and a pair of supporting bearings resting on each of said frames, of a tilting boom having one end bifurcated, each of the bifurcations being pivoted on a bearing on one side of the vehicle, and a hydraulic jack pivoted to the 5. other bearing on each side of the vehicle and pivotally connected to said boom.

5. A lifting boom for mounting on automotive vehicles having traction belts traversin track frames, comprising forwardly extending 6 members overlying the belts, hinge bearings on opposite sides of the vehicle for the inner ends of said members, .and means for supporting said hinge bearings directly above said belts on said track frames. l

6. A lifting device for mounting on an automotive vehicle having traction belts, comprising a forwardly extending boom structure having parallel portions overlying said belts, a plurality of hinge bearings disposed directly above saidl belts, said boom being pivoted in certain of said bearings, and a hydraulic Jack connected to each of said portions for exerting a lifting effort on the boom, said jacks being pivoted in others of said bearings. 1

8. An automotive lifting device adapted for mounting on a traction vehicle having crawler belts traversing track frames, said device including a bearing, means mounted on one of said frames adjacent the rear thereof for supporting the bearing, a boom pivotally supported in said bearing, a second bearing on said one of said frames ahead of the first mentioned bearing, and extensible means pivotally connected to said second bearing and to said boom, said means being 10 effective on extension to tilt the boom.

WILLIAM T. STEPHENS. 

